Next tonight, a very specific threat in the air. Often precedented warning about airplanes flying in the air. Brian Ross has the details tonight. Reporter: The airplane terror warning flight was stark and unprecedented. The U.S. Embassy in Guyana said Americans should avoid all flights on caribbean air from Guyana to the United States until at least Thursday, because of what it termed a specific but unconfirmed threat. This is out of an abundance of caution. This is unconfirmed threat information. Reporter: Today's flight to New York was allowed to land at Kennedy airport, met by three homeland security squads with portable x-ray scanners. Passengers said they were worried, but not enough to cancel their plans. I was scared of going on caribbean airlines but I have to take my chances. Reporter: U.s. Authorities have long been concerned about terror cells in Guyana. And one of the FBI's most wanted Al Qaeda top operatives, Adnan shukrujmah, is a native of Guyana, who grew up in New York and Florida, and is actively being hunted by the U.S. In Pakistan. The intensity of the ongoing hunt for a number of senior Al Qaeda leaders was seen in this new video of a capture of one of them, ansas Al Libi last October, obtained by "The Washington post." A white van cuts off the target's car, delta force members jump out, guns drawn, a second car blocks any escape. Up the street, a quick reaction force Koor pulls in to keep the scene clean. After an apparent struggle, Al Libi is pulled into the white van. The U.S. Forces sweep the area and then they are gone. It's all over in just a little over 60 seconds. Al Libi is now in New York awaiting trial for his role in the bombings of U.S. Embassies in Africa. Brian, this comes as there's new app report, an American target target Americans overseas. U.s. Officials have confirmed that is the case. They're watching one American citizen in particular, trying to decide whether it's legal to go ahead and kill him, because otherwise they think they can't get at him. Now to winter lms, where the weather is as warm as San

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